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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Coupled set of differential equations describing generalized Volterra problem of conflicting populations and application to plasma oscillations
Herzberg bands synthetic spectra matched to various spectrograms to determine vibrational populations of molecular O state in nightglow
Fifty-man space base population organization
Statistical sampling procedure for jimsphere winds aloft population
IR spectroscopy, determining relative populations of carbon dioxide vibrational energy levels by comparing emission intensities
Carbon dioxide molecular vibrational energy levels above carbon monoxide-oxygen premixed flame, discussing vibration modes leading to population inversion and relaxation time variance
He II 3s and 3d states mean lives and initial population as function of energy, analyzing emitted radiation intensity
Estimating total Y for finite population with unknown values
Confidence intervals and significance tests for mean of symmetrical population with smallest or largest outlier observation
Australian tektites population polygons of bulk specific gravity and refractive index, indicating variations in chemical composition
Population inversion in Cs133 ground state hyperfine levels, using CW GaAs laser at 77 K for optical pumping
Variable abyssal basalt populations, considering chemical analyses variations for ridges as function of ocean floor spreading rate
Arc heated plasma expansion through nozzle, observing population inversion of neutral carbon self-absorption UV atomic line
Internal short chain alkane populations of paraffinic hydrocarbons in tobacco teratoma and habituated tissue cultures
Solar low energy cosmic ray population anisotropy from satellite observations during flare event, describing rise time, decay, field alignment and time constant
RR Lyrae stars instability strip for halo population variables, presenting linear nonadiabatic approximate pulsation calculations with emphasis on blue edges location in H-R diagram
Near resonance charge exchange between ions of a large ionization potential gas such as helium or neon and vapors of metals such as zinc, cadmium, selenium, or tellurium has produced laser action in the metal ion gas. The possibility of obtaining population inversions in near resonant charge exchange systems (Xe-Ca, Xe-Mg, Xe-Sr, Xe-Ba, Ar-Mg, N-Ca) was investigated. The analysis is an initial value problem that utilizes rate equations for the densities of relevant levels of the laser gas (Ca, Ba, Mg, or Sr) and an electron energy equation. Electron excitation rates are calculated using the Bohr-Thomson approximation for the cross section. Approximations to experimental values of the electron ionization cross section and the ion-atom charge exchange cross section are used. Preliminary results have been obtained for the Ca-Xe system and show that it is possible to obtain gains greater than 10 to the 14th power/m with inversion times up to 8x10 to the minus 7th power second. A possible charge exchange laser system using a MPD arc plasma accelerator is also described.
Calculated coefficients relating the population in level n to its value in equilibrium are presented for various atomic levels under conditions of low temperature, density, and thermal radiation fields that may be expected in the interstellar medium. A thermal continuum such as that produced by an H II region is found to substantially change both the departure coefficients and their slope under conditions of low density.